Python Add Dictionary
Python Add Items to Dictionaries
In Python, dictionaries are versatile data structures that store data in key-value pairs. One of the key features of dictionaries is the ability to add new items dynamically. This lesson will guide you through the process of adding new entries to a dictionary and updating existing ones.
1. Adding Items to a Dictionary
To add an item to a dictionary, you simply specify a new key and assign a value to it. This operation is straightforward and allows you to expand your dictionary's contents as needed.
Example: Adding a New Item
python
1# Creating a dictionary for a smartphone
2smartphone_specs = {
3 "brand": "Samsung",
4 "model": "Galaxy S21",
5 "year": 2021
6}
7
8# Adding a new item for color
9smartphone_specs["color"] = "Phantom Gray"
10
11print(smartphone_specs) # Output: {'brand': 'Samsung', 'model': 'Galaxy S21', 'year': 2021, 'color': 'Phantom Gray'}
In this example, the new key "color" is added to the smartphone_specs
dictionary, allowing you to store more information about the smartphone.
2. Updating the Dictionary with update()
The update()
method is a powerful way to add or modify multiple items in a dictionary at once. This method takes a dictionary or an iterable of key-value pairs as its argument.
Example: Using update() to Add Items
python
1# Creating a dictionary for a laptop
2laptop_details = {
3 "brand": "Dell",
4 "model": "XPS 13",
5 "year": 2020
6}
7
8# Adding multiple items using update()
9laptop_details.update({"color": "Silver", "RAM": "16GB"})
10
11print(laptop_details) # Output: {'brand': 'Dell', 'model': 'XPS 13', 'year': 2020, 'color': 'Silver', 'RAM': '16GB'}
In this example, we use update()
to add both the "color" and "RAM" entries to the laptop_details
dictionary in one step.
3. Adding Items Using an Iterable
You can also use an iterable object, like a list of tuples, to add multiple key-value pairs at once. This can streamline the process when you have several items to add.
Example: Adding Items from a List of Tuples
python
1# Creating a dictionary for a book
2book_info = {
3 "title": "1984",
4 "author": "George Orwell",
5 "published": 1949
6}
7
8# List of new attributes as tuples
9new_attributes = [("genre", "Dystopian"), ("pages", 328)]
10
11# Adding new attributes using a loop
12for key, value in new_attributes:
13 book_info[key] = value
14
15print(book_info) # Output: {'title': '1984', 'author': 'George Orwell', 'published': 1949, 'genre': 'Dystopian', 'pages': 328}
In this example, we iterate through a list of tuples, adding each new attribute to the book_info
dictionary.